Follow blockchain research across journals, conferences, and preprint repositories.
2,611 results · page 92 of 109
Mohsen Minaei, Pedro Moreno-Sánchez, Aniket Kate
No abstract is available for this record.
Duc-Hiep Nguyen, Dinh-Nghia Nguyen-Duc, Nguyen Huynh Tuong, Hoang-Anh Pham
By using a decentralized peer-to-peer network together with public and distributed ledger to decentralize the central authority, Blockchain has shown its great potential with the success of Bitcoin. However, the blockchain technology can go beyond financial transactions. In this paper, we propose an approach that utilizes the blockchain technology to issue immutable digital certificates and improve the current limitations of the existing certificate verifying systems such as faster, more trusted, and independent of the central authority. Our prototype has been successfully deployed for several short-term courses at the Center of Computer Engineering, HCMC University of Technology, Vietnam. This result indicates that our proposed system is an appropriate solution adopting ICT for e-government, especially in certificate and diploma management.
Francesco Fusco, Maria Ilaria Lunesu, Filippo Eros Pani, Andrea Pinna
No abstract is available for this record.
Tuyet Duong, Alexander Chepurnoy, Hong-Sheng Zhou
In the past years, the security of Bitcoin-like protocols has been intensively studied. However, previous investigations are mainly focused on the single-mode version of Bitcoin protocol, where the protocol is running among full nodes (miners). In this paper we initiate the study of multi-mode cryptocurrency protocols. We generalize the recent framework by Garay et al (Eurocrypt 2015) with new security de nitions that capture the security of realistic cryptocurrency systems. e.g. Bitcoin with full and lightweight nodes. As an immediate application of our new framework, we analyze the security of existing blockchain pruning proposals for Bitcoin and Ethereum aiming to improve the storage e ciency of network nodes by pruning unnecessary information from the ledger.
Haibo Tian, Liqing Fu, Jiejie He
No abstract is available for this record.
Gaby G. Dagher, Praneeth Babu Marella, Matea Milojkovic, Jordan Mohler
Voting is a fundamental part of democratic systems; it gives individuals in a community the faculty to voice their opinion. In recent years, voter turnout has diminished while concerns regarding integrity, security, and accessibility of current voting systems have escalated. E-voting was introduced to address those concerns; however, it is not cost-effective and still requires full supervision by a central authority. The blockchain is an emerging, decentralized, and distributed technology that promises to enhance different aspects of many industries. Expanding e-voting into blockchain technology could be the solution to alleviate the present concerns in e-voting. In this paper, we propose a blockchain-based voting system, named BroncoVote, that preserves voter privacy and increases accessibility, while keeping the voting system transparent, secure, and cost-effective. BroncoVote implements a university-scaled voting framework that utilizes Ethereum’s blockchain and smart contracts to achieve voter administration and auditable voting records. In addition, BroncoVote utilizes a few cryptographic techniques, including homomorphic encryption, to promote voter privacy. Our implementation was deployed on Ethereum’s Testnet to demonstrate usability, scalability, and efficiency.
Baokun Zheng, Liehuang Zhu, Meng Shen, Xiaojiang Du · 10 authors
No abstract is available for this record.
Michał Pawlak, Aneta Poniszewska-Marańda, Natalia Kryvinska
There are many existing voting solutions which have different benefits and issues. The most significant ones are lack of transparency and auditability. Recently developed blockchain technology may be a solution to these issues. The paper describes the use of intelligent agents and multi-agent system concept for Auditable Blockchain Voting System (ABVS), which integrates e-voting process with blockchain technology into one supervised non-remote internet voting system which is end-to-end verifiable.
Sepideh Avizheh, Reihaneh Safavi–Naini, Siamak F. Shahandashti
BIP70 is the Bitcoin payment protocol for communication between a merchant and a pseudonymous customer. McCorry et al. (FC~2016) showed that BIP70 is prone to refund attacks and proposed a fix that requires the customer to sign their refund request. They argued that this minimal change will provide resistance against refund attacks. In this paper, we point out the drawbacks of McCorry et al.'s fix and propose a new approach for protection against refund attacks using the Bitcoin multi-signature mechanism. Our solution does not rely on merchants storing refund requests, and unlike the previous solution, allows updating refund addresses through email. We discuss the security of our proposed method and compare it with the previous solution. We also propose a novel application of our refund mechanism in providing anonymity for payments between a payer and payee in which merchants act as mixing servers. We finally discuss how to combine the above two mechanisms in a single payment protocol to have an anonymous payment protocol secure against refund attacks.
Christos Patsonakis, Katerina Samari, Mema Roussopoulos, Aggelos Kiayias
Public-key infrastructures (PKIs) are an integral part of the security foundations of digital communications. Their widespread deployment has allowed the growth of important applications, such as, internet banking and e-commerce. Centralized PKIs (CPKIs) rely on a hierarchy of trusted Certification Authorities (CAs) for issuing, distributing and managing the status of digital certificates, i.e., unforgeable data structures that attest to the authenticity of an entity’s public key. Unfortunately, CPKI’s have many downsides in terms of security and fault tolerance and there have been numerous security incidents throughout the years. Decentralized PKIs (DPKIs) were proposed to deal with these issues as they rely on multiple, independent nodes. Nevertheless, decentralization raises other concerns such as what are the incentives for the participating nodes to ensure the service’s availability.
Geoffrey Goodell, Tomaso Aste
Modern retail banking creates a kind of panopticon for consumer behaviour, ultimately promising to implement a mechanism that binds all of the financial activities undertaken by an individual to a single, unitary identity. In the age of Big Data, consumers have legitimate reasons to resist such surveillance, particularly in cases wherein monitoring is carried out without their knowledge and judgments based upon such monitoring are used to disincentivise or punish legitimate activities. The risk to consumers increases with the ever-increasing share of financial transactions that are performed electronically. Cryptocurrencies offer an alternative to traditional methods of electronic value exchange, promising anonymous, cash-like electronic transfers, but in practice they fall short for several key reasons. We consider the false choice between total surveillance, as represented by banking as currently implemented by institutions, and impenetrable lawlessness, as represented by privacy-enhancing cryptocurrencies as currently deployed. We identify a range of alternatives between those two extremes, and we consider two potential compromise approaches that offer both the auditability required for regulators and the anonymity required for users
Indra Deep Mastan, Souradyuti Paul
Mounting deanonymization attacks on the unreachable Bitcoin nodes – these nodes do not accept incoming connections – residing behind the NAT is a challenging task. Such an attack was first given by Biryukov, Khovratovich and Pustogarov based on their observation that a node can be uniquely identified in a single session by their directly-connected neighbouring nodes (ACM CCS’15). However, the BKP15 attack is less effective across multiple sessions. To address this issue, Biryukov and Pustogarov later on devised a new strategy exploiting certain properties of address-cookies (IEEE S&P’15). Unfortunately, the BP15 attack is also rendered ineffective by the present modification to the Bitcoin client.
Chul‐Jin Kim
No abstract is available for this record.
Bin Yu, Joseph K. Liu, Amin Sakzad, Surya Nepal · 7 authors
No abstract is available for this record.
Usman Chohan
No abstract is available for this record.
Baocheng Wang, Jiawei Sun, Yunhua He, Dandan Pang · 5 authors
Based on the blockchain, homomorphic ElGamal encryption and ring signature, an electronic voting scheme based on blockchain is proposed for large-scale voting, which has the properties of decentralization, self-management, non-interactive and free-receipt, furthermore the one-time ring signature ensures the anonymity of the vote trading in the blockchain. The public verifiable billboards guarantee the voting fair, and the miner nodes provides ciphertext ballot counting service makes large-scale voting feasible. Finally, we analysis the security of the blockchain voting system and present the performance in large-scale nodes.
Ivan Damgård, Ji Luo, Sabine Oechsner, Peter Schöll · 5 authors
No abstract is available for this record.
Wei Shao, Hang Li, Mengqi Chen, Chunfu Jia · 6 authors
No abstract is available for this record.
Kashif Mehboob Khan, Junaid Arshad, Muhammad Mubashir Khan
Electronic voting or e-voting has been used in varying forms since 1970s with fundamental benefits over paper-based systems such as increased efficiency and reduced errors. However, challenges remain to the achieving of wide spread adoption of such systems, especially with respect to improving their resilience against potential faults. Blockchain is a disruptive technology of the current era and promises to improve the overall resilience of e-voting systems. This article presents an effort to leverage benefits of blockchain such as cryptographic foundations and transparency to achieve an effective scheme for e-voting. The proposed scheme conforms to the fundamental requirements for e-voting schemes and achieves end-to-end verifiability. The article presents details of the proposed e-voting scheme along with its implementation using Multichain platform. The article also presents an in-depth evaluation of the scheme which successfully demonstrates its effectiveness to achieve an end-to-end verifiable e-voting scheme.
Elie Kfoury, David Khoury
No abstract is available for this record.
Christian Badertscher, Juan A. Garay, Ueli Maurer, Daniel Tschudi · 5 authors
No abstract is available for this record.
Gholamreza Ramezan, Cyril Leung
In this paper, we propose a novel blockchain‐based contractual routing (BCR) protocol for a network of untrusted IoT devices. In contrast to conventional secure routing protocols in which a central authority (CA) is required to facilitate the identification and authentication of each device, the BCR protocol operates in a distributed manner with no CA. The BCR protocol utilizes smart contracts to discover a route to a destination or data gateway within heterogeneous IoT networks. Any intermediary device can guarantee a route from a source IoT device to a destination device or gateway. We compare the performance of BCR with that of the Ad-hoc On‐Demand Distance Vector (AODV) routing protocol in a network of 14 devices. The results show that the routing overhead of the BCR protocol is 5 times lower compared to AODV at the cost of a slightly lower packet delivery ratio. BCR is fairly resistant to both Blackhole and Greyhole attacks. The results show that the BCR protocol enables distributed routing in heterogeneous IoT networks.
Xuechao Yang, Xun Yi, Surya Nepal, Fengling Han
No abstract is available for this record.
Adem Efe Gencer, Soumya Basu, Ittay Eyal, Robbert van Renesse · 5 authors
Blockchain-based cryptocurrencies have demonstrated how to securely implement traditionally centralized systems, such as currencies, in a decentralized fashion. However, there have been few measurement studies on the level of decentralization they achieve in practice. We present a measurement study on various decentralization metrics of two of the leading cryptocurrencies with the largest market capitalization and user base, Bitcoin and Ethereum. We investigate the extent of decentralization by measuring the network resources of nodes and the interconnection among them, the protocol requirements affecting the operation of nodes, and the robustness of the two systems against attacks. In particular, we adapted existing internet measurement techniques and used the Falcon Relay Network as a novel measurement tool to obtain our data. We discovered that neither Bitcoin nor Ethereum has strictly better properties than the other. We also provide concrete suggestions for improving both systems.